Rebels seized a border crossing on the demilitarized zone between Israel and Syria on Thursday, activists said, as heavy clashes raged between the opposition and President Bashar al-Assad's forces, according to Reuters.

The Britain-based Syrian Observatory for Human Rights said it was the first time rebels seized a border crossing next to the Israeli occupied Golan Heights, but it was unclear whether the anti-Assad fighters would be able to hold the site, Reuters reported.

“The rebels have seized the crossing near the old city of Quneitra in the occupied Golan Heights,” said Rami Abdelrahman, head of the Observatory. “There are heavy explosions and fierce clashing ongoing in the area,” Reuters reported.